1. Field of the Invention
The present invention relates to a method and an apparatus for the decontamination of a substance contaminated with radioactivity produced in a nuclear power station or the like, and to a method and an apparatus for the decontamination of a material used for said decontamination.
2. Description of the Prior Art
Heretofore, in a nuclear power station, with the passage of time substances contaminated with radioactivity are produced due to contact of apparatus and the parts thereof with radioactivity.
Such contaminated apparatus or parts are generated as replaced or disposed forms at the time when the apparatus are subjected to routine inspection or overhaul.
Otherwise, there occurs no replacement of the part, however, some apparatus contaminated are generated to be necessarily coated.
The degree of contamination of these contaminated substances can be out of the specified range according to safety standards. To dispose of these substances large size substances are cut into small size substances, contained in metal drums, and then they are usually confined in abandoned mines or the like, or kept or dumped in storage places which are constructed in regions with few inhabitants located apart from urban areas.
In the present invention, said terms "keeping and dumping" are unified as one word "dumping" for convenience.
The amount of substances contaminated with radioactivity stated above increases every year by the operation of nuclear power stations, resulting in lack of places to dump these substances. New waste-dumping places, therefore, become necessary. Then when a new waste-dumping place is selected, however, the inhabitants near the place tend to make an opposition movement leading to social problems. The present invention is intended to solve such troubles. The object of the invention is to provide a method and an apparatus for the decontamination of substances contaminated with radioactivity which comprises decontaminating substances contaminated with radioactivity as mentioned above, enabling the decontaminated substances to have less radioactivity than that required by safety standard, therefore, allowing the substances to be dealt with as general industrial wastes, and enabling the use of a greatly reduced area of waste-dumping place. Another object of the invention is to to provide a method and an apparatus for the decontamination of materials used for the decontamination of the substance mentioned above which comprise decontaminating fully said materials, regenerating the materials, and permitting the re-use thereof.